Urinary incontinence is a condition affecting 200 million people worldwide that significantly reduces quality of life. Diagnosis of urinary incontinence can range from a simple clinical evaluation based on history and a physical exam to more complex tests, such as a clinical urodynamics examination, to determine if the patient has stress urinary incontinence or urgency urinary incontinence due to overactive bladder or neurogenic detrusor overactivity. Diagnosis of lower urinary tract dysfunction with urodynamics has historically relied on data acquired from two or more sensors using nonphysiologically fast cystometric filling. Extended ambulatory urodynamics testing can provide more data collected at physiologically normal fill rates. However, this two-sensor system provides an inconvenient and uncomfortable solution for extended ambulatory urodynamics testing. An alternative method of measuring bladder activity over extended durations at natural fill rates would improve diagnosis of urinary incontinence.
For treatment of urinary dysfunctions, electrical stimulation has been shown to effectively inhibit unwanted bladder contractions in both spinal cord injury patients and neurally intact patients. Currently, state-of-the-art electrical stimulation has focused on open-loop neuromodulation. However, this open-loop stimulation is not ideal because the neural pathways could become habituated to continuous stimulation of sensory nerves, potentially reducing the effectiveness of stimulation over time. Stimulation settings may need to be adjusted over time, typically by the clinician. In addition, individuals with neurogenic detrusor overactivity require feedback of bladder activity in the absence of sensation to determine when to empty their bladders, and those with sensation may not wish for stimulation to be continually active. Accordingly, closed-loop control would improve such neuromodulation, but the closed-loop control requires feedback to determine bladder activity.